The present invention relates in general to a shroud for surrounding a cooling fan of an internal combustion engine, and, more specifically, to a shroud with a hinged portion for facilitating assembly onto an engine in an engine compartment of a vehicle.
In one common assembly process for automotive vehicles, an internal combustion engine is mounted onto the vehicle frame and then a vehicle body is lowered onto the frame/engine assembly. Typically, the body carries a cooling module (e.g., a radiator, condenser, and fan shroud). When an engine-driven fan is used, the fan is already installed on the engine at the time when the body/cooling module is added to the frame. In order to avoid interference between the shroud and fan during placement of the cooling module, the barrel portion of the shroud has been provided with an articulating or removable segment that can be moved into the proper position after placement of the cooling module.
For ease of assembly, a movable barrel segment is preferably pre-installed on the shroud which can be pulled into position after installation of the cooling module over the engine. This pivotable segment is mounted by a hinge in order to swivel between i) a shipping position with the segment retracted within the shroud main body, and ii) a locked position which encloses the fan. To prevent damage to the shroud components during shipping and handling of the shroud, it is desirable to secure the movable segment at the retracted position prior to vehicle installation when it is moved to the extended position around the fan. It is also desirable that the movement from the retracted position to the extended position can be achieved easily and robustly, simultaneously ensuring strong retention at the extended position without demanding any difficult assembly operations. In one conventional design, a molded pin or clip has been used as a hinge. Spring arms on the clip would compress in order to install the clip through pivot holes on the two shroud pieces and then would create enough friction within the hinge to prevent the movable segment from pivoting freely. The clips, however, are subject to breakage at an unacceptably high rate, and performance is less than optimal because the relatively high amount of friction used for keeping the movable section in place during shipping and handling is also present during the entire swiveling movement to enclose the fan, which increases the assembly efforts.